1984 300 Turbo Diesel
I have half of your problem- the popping sound. On the car body itself, the weld that holds the check strap assembly has broken through. You can visibly see the broken weld in the door frame. A shop said they could weld it back for a mere $85. I wish I knew a farmer here in Lee's Summit, Missouri, that would do it for a story or two- or a 6 pack of beer.